(NaturalNews) A chemical used in nonstick cookware increases children's risk of developing attention deficit hyperactivity disorder (ADHD), according to a study conducted by researchers from Boston and Harvard Universities and published in the journal Environmental Health Perspectives.

The findings were previously presented at the annual meeting of the International Society of Environmental Epidemiology in Ireland.

Researchers took blood samples from children and compared their levels of a chemical known as C8 with their risk of being diagnosed with ADHD. They found that every 1 part per billion increase in C8 concentration in the blood corresponded to a 12 percent increase in the risk of ADHD.

ADHD is one of the most common and fastest-growing developmental nervous disorders in children. Symptoms include inattentiveness, fidgeting, impulsiveness and hyperactivity.

C8, also known as perfluorooctanoic acid (PFOA) is used to manufacture nonstick coatings, food packaging and stain- and water-resistant fabrics. It is in the family known as perfluorinated chemicals (PFCs).

PFCs persist indefinitely in the environment and have been shown to build up in animal tissue; C8 and other PFCs have been found in the blood of people around the world.

Increasing evidence suggests that even very low levels of C8 -- those commonly found in people worldwide -- have the potential to produce health problems including endocrine (hormone) disruption, cancer, liver damage, immune problems, developmental damage, birth defects and high cholesterol.

Other members of the PFC family of chemicals have also been linked to equally severe effects. One study, published in 2008, found that higher exposure to PFCs is correlated with a delay in the age at which a baby can sit without assistance.

No federal standards exist to regulate human PFC exposure.

In the Parkersburg, W.V. area, thousands of residents have been exposed to high levels of C8 due to contamination of their water supply by a nearby DuPont factory.